The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
A continuously variable transmission (“CVT”) typically includes a belt and pulley system that operatively couples a rotary power source, such as an engine or electric motor, to a double gear final drive unit. The belt and pulley system generally includes first and second pairs of pulley cones having a torque transmitting belt or chain extending between the cone pairs. Each pulley cone pair includes an axially stationary pulley member and an axially movable pulley member. Each movable pulley member is axially adjustable with respect to the stationary pulley member by a hydraulic system. The hydraulic system provides primary and secondary hydraulic pressures to the respective movable pulley members to adjust the running radius of the first and second pulley cone pairs which in turn controls the output/input ratio of the continuously variable transmission. Movement of the cones steplessly or continuously varies the ratio of an input speed to an output speed. With the continuously variable transmission, small but effective ratio changes can be attained. This is in contrast to a fixed gear ratio unit where any ratio changes are step values.
Known pulley designs exhibit high axial loading on the shaft due to friction. To minimize the axial loading on the shaft, high capacity bearings are used to mount the shaft, resulting in both cost and weight increase to the power plant. The high capacity bearings further increase a space envelope of the assembly, thereby increasing an axial length of the transmission.
Known variator designs for CVT transmissions have their advantages, however, there is a need in the art for a CVT variator that limits axial loads on the output shaft allowing the elimination of the high capacity bearings now used.